Combined refrigerating compressor and oil separator



April 14, 1953 L. F. CLERC COMBINED REFRIGERA'YING COMPRESSOR AND 01:. SEPARATOR Filed April 19, l948 5 Sheets-Sheet 3 JNVENTOR. LEONARD F. CLERC A 7' TORNE Y Patented Apr. 14, 1953 UNITED STATES PATENT OFFICE COMBINED REFRIGERATING COMPRESSOR AND OIL SEPABATOR Leonard F. Clerc, Detroit, Mich.

Application April 19, 1948, Serial No. 21,955

7 Claims. 1

This invention relates to compressors, and particularly to refrigerating compressors of the rotary type.

An object of the invention is to generally improve compressors, and to provide a device of the character indicated in which the entire compressor body, except a small surface at one end, is enclosed and hermetically sealed in a housing which forms an oil separator, a pressure equalizing chamber, and an oil reservoir.

Another object of the invention is the provision of a device of the character indicated, in which one of the principal parts of the device comprises an inexpensive casting in which is positioned hardened steel inserts which serve as wear resisting working parts.

A further object of the invention is'to provide a refrigerant compressor in which the compressor body is formed of a casting having two principal sections, in one of which sections the compressor parts are assembled and housed, and in the other section is housed the drive shaft and shaft seal, whereby the shaft and shaft seal may be independently removed without disturbing the compressor proper.

Another object of the invention is the provision of a hermetically sealed compressor which is constructed and arranged so that it may be driven by an externally positioned motor.

Another object of the invention is the provision of a device of the character indicated, which is constructed and arranged so that the comparatively high internal pressures maintained therein serve to move the hermetically sealed parts into closer sealing relation with respect to each other.

Another object of the invention is the provision of a device of the character indicated which is constructed and arranged so that the rotor substantially floats freely on its drive shaft and between its defining side walls by virtue of the high pressures and the lubricating mediums provided therein.

Another object of the invention is the provision of a device of the character indicated, in which the compressed gases are discharged from the compressor tangentially into a chamber closely surrounding the compressor.

Another object of the invention is the provision of a device of the character indicated, which is constructed and arranged so that upon each revolution of the compressor rotor a predetermined amount of screened lubricating medium is injected under high pressures from the oil reservoir to and about all of the moving parts of the compressor, thereby insuring a cushioning film of oil for the moving parts, and obviating the difliculty of an excessive amount of lubrication entering the compressor.

Another object of the invention is the provision of a device of the character indicated which is constructed and arranged so that during the operation thereof an effective oil seal is main tained between the moving and non-moving parts of the compressor.

Another object of the invention is the provision of a hermetically sealed compressor which is constructed and arranged so that the oil seal assembly for the drive shaft may readily be removed from one end of the device without disturbing the working parts of the compressor.

Another object of the invention is the provision of a device which is constructed and arranged so that the lubricating medium is substantially removed from the compressed gases before the latter are discharged into the refrigerator line, thus obviating the difiiculty of an excessive amount of lubrication being discharged into the high pressure line.

Another object of the invention is the provision of a device of the character indicated which is constructed and arranged so that the main body of the lubricating medium is prevented from entering the gas intake port of the compressor body.

Another object of the invention is the provision of a device of the character indicated, which is constructed and arranged so that the internal parts of the compressor receive a predetermined amount of a screened lubricant, which is injected into the area of the compressor defined by two vanes at the instant said area is on the low side of the compression cycle.

Another object of the invention is'the provision of a device of the character indicated, which is constructed and arranged so that there is an equalized pressure on all of the moving parts of the compressor at the moment of starting the compressor, thereby reducing the amount of power input necessary to initially move the compressor, and obviating the necessity of bucking a high head pressure upon starting.

Another object of the invention is the provision of a vane type rotary compressor which is provided with means to positively reciprocate the vanes in the rotor slots, and means to relieve the back pressure in the rotor slots upon the inward stroke of each vane.

Another object of the'invention is to provide a .vane type rotary compressor in which each vane is provided with oppositely disposed rollers adapted to engage twin acting cam surfaces, whereby the vanes are positively reciprocated in the rotor slots, and whereby a predetermined clearance is maintained between the outer ends of the vanes and the rotor housing, which clearance is positively sealed by means of a lubricant.

Another object of the invention is the provision of a vane type rotary compressor which is constructed and arranged so that the vanes are free to float sideways within the rotor slots, whereby an equalized clearance may be maintained onopposite sides of said vanes by the: internal pressure maintained in said device.

A further object of the invention is to provide a device of the character described in which the oil seal assembly for the drive shaft ismounted on the drive shaft between two main shaft bearings, whereby the oil seal is held inperfect alignment.

Another object of the invention is to provide a vane type rotary compressor in which the reciprocation of the vanes is positively controlled so that a predetermined clearance of close tolerance may be maintained at all times between the working parts, whereby when the device is con.- nected in a refrigerating. assembly the unit may be charged with a refrigerant through the low side without danger of forcing the lubricating oil into the refrigerator line.

Another object of the invention is to provide a device of the character indicated, which is constructed and arranged. with a check valve in the suction side fitting of the compressor intake port, thereby eliminating the tendency of any liquified refrigerant to back into the suction line from the condenser when the compressor is idle.

Another object of the invention is to provide a device of the character indicated, which is constructed and arranged without a check valve on the discharge side of the compressor, thereby insuring an equalized pressure throughout the oil separator and the compressor when the compressor is idle, thereby eliminating the customary starting load and permitting the use of a low powered propulsion unit with it attendant economies.

Another object of the invention is to provide a refrigerant compressor which may be operated at a comparatively high speed with the result that a greater volume of gas may be compressed in a given period of time, with a substantial saving of motive power.

A further object of the invention is to provide a device of the character indicated, which is constructed and arranged so that the compressed refrigerant gases are discharged from the compressor into a chamber, whereby the gases are preliminarily cooled before being discharged into the refrigeration line, and whereby the temperature of the refrigerant is correspondingly reduced.

The foregoing and other objects and advantages of the invention will become more apparent as the description proceeds, reference being made from time to time to the accompanying drawings, forming part of the within disclosure, in which drawings:

Fig. 1 is a longitudinal sectional view of a device embodying the invention taken substantially on the line ll of Fig. 2.

Fig. 2 is a section taken on the line 22 of Fig. 1.

Fig. 3 is a section taken through the liner ring, a perspective view of which is shown. i Fig. 9.

Fig. 4 is a front view of one of the vanes.

Fig. 5 is a section taken on the line 5--5 of Fig. 4.

Fig. 6 is a perspective view of the casting comprising part of the compressor body.

Fig. 7 is a perspective view of the eccentric cam member.

Fig. 8 is a perspective of the front cam ring employed to formthe outer guide surface for vane rollers and to form the front enclosure for the rotor.

Fig. 9 is a perspective view of the liner ring which serves to form the enclosure around the outer surface of the rotor.

Fig. 10 is a perspective view of the rotor with the vanes inserted with rollers.

Fig. 11 is a perspective view of the rear cam ring employed to form the outer guide surface for vane rollers and to form the rear enclosure for the rotor.

Fig. 12 is a perspective View of the end closure cover for the casting shown in Fig. 6.

Fig. 13 is a perspective view of the drive shaft with the oil seal and end closur member in position.

Fig. 14 is a perspective view of the cylindrical housing which forms part of the oil separator, oil reservoir and pressure equalizing chamber.

Fig. 15 is a perspective view of the threaded coupling which connects the cylindrical housing (Fig. 14) to the casting (Fig. 6) at the suction side of the compressor body.

Fig. 16 is a perspective View of the end closure cap for the cylindrical housing (Fig. 14).

Referring now more particularly to the drawings, it will be understood that in the embodiment herein disclosed, the reference character 20 (Figs. 1, 2 and 14) indicates a cylindrical housing which may be formed of a suitable length of heavy steel tubing, and to which is preferably secured, as by welding 2| (Fig. l) the. drilled and tapped bosses 22 and 23 (Figs. 1 and 2) to which are respectively connected the fittings 24 of the suction line 25 and discharge line 26 by means of machine bolts 21, or other suitable means. Gaskets 28 are provided between the bosses 22 and 23 and the fittings24.

The cylindrical housing 20 is provided with a ring 29 (Figs. 1 and 14) which is welded into the rear end, as at 30. The ring 29 serves as an abutment member for the casting flange 3| of the casting 32 (Figs. 1 and 6) so that during the operation of the device the casting 32 is pressed tightly against the flange gasket 33 (Fig. 1) by the internal pressure of the device which is a novel feature of the invention.

The casting 32 (Figs. 1 and 6) is provided with studs 34 which engage recesses 35 (Figs. 1 and 14) formed on the inside surface of the ring 23 and serve as means to locate the casting 32 therein, and secure the casting 32 against rotation. The cylindrical housing 20 (Figs. 1, 2 and 14) is provided with supports 36 and an end closure cap 3'! (Figs. 1 and 16) which is secured as hereinafter described.

The casting 32 (Figs. 1, 2 and 6) is preferably made of a. non-porous metal such as Mehinite and is provided with an extension member 38 (Figs. 1 and 6) which is drilled and tapped, as at 39, to accommodate machine screws 43 (Fig. 1) whereby the end closure member 4| (Figs. 1 and 13) is held in place and is secured tightly against the gasket 42 (Figs. 1 and 6) between the extension member 38 and the end closure member 4|.

'Ihe casting 32 (Fig. 1) is provided with an opening 43 which is adapted to accommodate the oil seal assembly 44 which is of special design, and which is also adapted to utilize the internal pressure of the device. The oil seal rear section 45 is pressed into place and abuts against a shoulder 46 formed on the end closure member 4|, whereby it is held stationary while creating a sealing action between the surfaces of the oil seal rear section 45 and the front section 41 which revolves with the shaft 48. The seal assembly 44 is held in adjustable position by means of a spring 49 which in turn is held against longitudinal movement on the shaft 48 by a floating oil seal bushing 50, which abuts against the end surface of the high lead bronze bearing bushing and seals it around the shaft 48. The shaft 48 is held in position by the shaft shoulder 52 which rides against the inner end face 52A of the rear high lead bronze bearing bushing 53. The oil seal assembly 44 may be removed and replaced at any time without disturbing the compressor.

The casting 32 (Fig. 1) is also provided with a peripheral opening 54, the lower part of which serves as an oil reservoir, the upper part of which serves as a refrigerant collector.

Radial bores 55 (Fig. 1) extend into the casting opening 43 so that lubricant may reach the working parts positioned on the interior of the casting opening 43. The casting 32 (Figs. 1 and 2) is provided with passageways 56 to maintain communication between the peripheral opening 54 and the oil separator and reservoir 51 which is formed between the end of the casting 32, the cylindrical housing 20, and the end closure cap 3?.

A keyway 58 (Fig. 1) is formed in the front end of the casting 32, through which the casting is keyed to the eccentric cam member 59. The circular body 6! (Figs. 1 and 7) of the eccentric cam member 59 closes the end of the keyway 58 (Fig. l) which leads to the enlarged opening 60 formed in the front end of the casting 32, which said enlarged opening 60 is adapted to accommodate the working elements of the compressor proper which I will now describe.

Mounted on a bearing bushing 5| (Figs. 1 and 7) is a hardened steel cam member 59 which consists of a circular body El and a collar member 62 which are formed integrally of a single piece of metal but machined so that the circular body portion BI is eccentric to the circular member 62 portion. Positioned. around the circular collar member portion 62 of the eccentric cam member 5!) is a hardened steel, front cam ring 63 (Figs. 1 and 8) the inside diameter of which cam ring 63 is larger than the outside diameter of the circular collar member 62 of the eccentric cam member 59, whereby a raceway 64 (Figs. 1 and 2) is defined between the outer periphery of the circular collar member 62 and the inside periphery of the front cam ring 63 for the accommodation of rollers hereinafter described.

The rollers 65 and 6B and others (Figs. 1, 2, and are mounted on each side of the roller spindles 6'! and 68 which are formed as part of the vane 69 (Figs. 1, 2, 4, 5 and 10).

A cast iron liner ring 1!] (Figs. 1, 2, 3 and 9) is mounted inside of the enlarged opening 60 (Figs. 1 and 2) and at one side engages the undercut portion H (Fig. 1) of the hardened steel front cam ring 63. The cast iron liner ring 10 (Figs. 2, 3 and 9) has an intake slot 12 and an exhaust slot 13. It will be noted, that the exhaust slot 13 is formed in an angular position extending outwardly from the inside surface of the cast iron liner ring 10 and terminates in a narrow opening at the outer face of the cast iron ring 10 so that the compressed gases are discharged in a substantially tangential direction to the direction of rotation of the rotor 14, in the form of a fine vapor, which has a minimum of oil mixed therewith, and which is slightly precooled by its being discharged through the comparatively small exhaust port 13 into the larger area 51 of the oil separator, where some of the heat is dissipated through the oil separator housmg.

The exhaust slot 13 (Fig. 2) communicates with an opening l5 formed in the top of the casting 32 through which the compressed gases enter the oil separator 51 (Figs. 1 and 2). As the compressed gases strike the deflector 16 the oil therein being heavier falls downward into the lower section of the oil reservoir 51 (Fig. 1) and the gases pass through the slot ll into the peripheral opening 54 and hence out through the discharge port 18 and into the pressure line 26 through the fitting 24.

The rotor 14 (Figs. 1, 2 and 10) is a comparatively narrow Mehinite cast iron circular member having a hexagonal central opening 19 adapted to engage the hexagonal end ill] (Figs. 1 and 13) of the shaft 48 so that the rotor 14 (Fig. 1) may be rotated with the shaft 48. The shaft 48 is directly driven by a motor (not shown) or by a pulley 8! which may be belted to a motor (not shown).

An important feature of the invention resides in the fact that the rotor '14 (Fig. 1) is mounted on the double bearinged shaft 48 in such manner that it may freely float axially on the shaft 48, so that it tends to automatically center itself between the front and rear cam rings 63 and 82 under the influence of the internal pressure maintained in the device.

The rotor 14 (Figs. 2 and 10) is also provided on each side with concentric grooves 83 which are spaced from the outer periphery of the rotor 14,- and assists in the lubrication of the device as hereinafter described.

Apertures 84 and 85 (Figs. 2 and 10) extend through the rotor 14 and communicate at either side thereof with the concentric grooves 83. The grooves 83 and the apertures 84 and 85 communicate with aperture 85 (Figs. 1 and 11) which is formed in the hardened steel rear cam ring 82, and also communicate with an aperture 8! (Figs. 1 and 12) formed in the end closure cover 88 which is drilled and tapped, as at 89 (Fig. 1) to accommodate the oil tube fitting 99 to which is secured the tube 9| which extends downwardly well below the oil level 92 of the device into a fine screen oil protector 93, whereby a metered amount of screened oil from the oil reservoir 51, which is under high pressure, is shot into the fine screen oil protector 93 hence into the tube 9| and discharged through the cover aperture 81 into the aperture 86 and into the compressor as each aperture 84 and 85 of rotor M passes the aperture 86. This insures an even distribution of oil to both sides of the rotor 14 and assists in the proper lubrication of the vanes 69.

Each vane 69 and others not specifically given reference characters, are formed as shown in Figs. 4 and 5 with integral spindles 61 and 63 and angular end faces 94, so that during the sweep of the vanes 69 (Fig. 2) around the inside surface of the cast iron liner ring 10, there is always an accumulation of oil picked up just ahead of each vane 69, this insures a frictionless oil seal between the angular end face 94 7 of the vane 69 and the, inner periphery of the cast iron liner ring 10.

The rotor 14 (Figs. 2and' 10) is provided with radial slots 95 in which are adapted to reciprocate the hardened steel vane 69 and the other vanes which are not specially numbered. The vanes 69 are formed as shown in Figs. 1 and 5, and are also provided at the front and rear surface with relief pressure grooves 98 so that oil may reach each working surface of the vanes 69 (Fig. 2) and the rotor radial slots 95. The grooves 96 also serve to relieve the gas and oil pressure created betweenv the end of the vanes, 69 as at 9 on their inward stroke. This greatly reduces the power required to rotate such a device, at the same time supplying through the bores 98 formed in the rotor M an oil film to each inner working surface of the hexagonal central opening 19 (Fig. 1) and hexagonal surfaces of the end 89 of the shaft 48.

The rollers 65 and 65 and others not specifically numbered (Figs. 1 and 2) are positioned to revolve on the integral roller spindles 61 and 88, and travel in the raceways 6d and 185. An oil film is always maintained between the working faces of the rollers 65 and B6 and the inner face of the circular collar member 82 and outer periphery 164 of the hardened steel bushing H13, and the faces 99 of the front and rear hardened steel cam rings 63 and 82. An oil film is also maintained between the ends of the vanes 69 and the cast iron liner ring 1%, whereby their clearance is sealed.

The hardened steel rear cam ring 82 (Figs. 1 and 11) is similar to the hardened steel front cam ring 63 (Figs. 1 and 8) except that it has the aperture 86 (Figs. 1 and 11) and it is reversed whereby its shoulder IE is adapted to engage the opposite side of the cast iron liner ring Hi, as at I91.

The casting 32 (Figs. 1 and 6) is provided with an end closure cover 88 (Figs. 1 and 12) having an inturned hub I92 which is provided with a hardened steel bushing I03 pressed thereon. The outer periphery I04 (Fig. 1) of the hardened steel bushing I03, together with the inner periphery of the hardened steel rear cam ring 82 form the rear raceway I for the rollers 66.

The end closure member 88 (Figs. 1 and 12) is provided with bolt holes I06 and locating lugs 101, which are adapted to engage recesses (not shown) formed in the casting 32 (Fig. 1). The end closure member 88 is secured to the casting 32 by means of machine screws H18 which engage the drilled and tapped holes 109 formed in the casting 32.

The end closure cup 31 (Figs. 1 and 16) is provided with a central opening Hi] (Fig. 1) and a threaded hub HI which is welded thereto, as at H2, and through which is extended a long machine bolt H3 adapted to contact and put pressure on the end closure member 88 of the casting 32. The end of the long machine bolt H3 is welded over, as at H4, and the end closure cap 31 is welded, as at H5, to the cylindrical housing 20.

The high pressure created within the device between the end closure member 88 and the end closure cap 31 will eXert an even pressure against the end closure member 88 thereby forcing the end closure member 88 tightly against the end of the casting 32., which in turn will press the casting flange 3| against the flange gasket 33 which in turn will be pressed tighter against the ring 29 of the cylindrical housing 20' to seal the 8 parts. This is an important feature of the in-. vention.

The cylindrical housing 211 (Figs. 2 and 14) is secured to the casting 32 (Figs. 2 and 6) bymeans of a threaded coupling H6 (Figs. 2 and 15) which extends through the coupling port 111 (Figs. 2 and 14) of the threaded boss 22 of the cylindrical housing 23 and is threaded into the suction port H8 (Figs. 2 and 6) of the casting 32.

A gasket 28 surrounds the opposite end of the threaded coupling HS, as at H9. A fine oil screen is inserted into the end of the threaded coupling H6 and when the fitting 241 is drawn down tightly by the machine bolts 21 the fine oil screen I20 is imbedded into the gasket 28 and the gasket 28 seats and seals its self tightly between the outer end of the coupling port Ill and the opposite end of the threaded coupling HE.

A conventional check valve (not shown) is provided at any suitable place on the suction side of the device, but I prefer not to employ a check valve on the pressure side of the device for the reason that it is desirable when the device is idle to maintain the same pressure throughout the compressor and oil separator as is maintained in the condenser and receiver (not shown). This provides a distinct advantage in the operation of the device in that the compressor can again be started without bucking a head pressure.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In a device of the character described, a casting having a central passageway, counterbores at each end of said passageway, end closure members for said counterbores, a shaft extending through one of said end closure members and through said passageway and into the opposite counter-bore, a rotary compressor assembled in said last named counter-bore and arranged to be driven by said shaft and a gas tight housing enveloping all but one side of said casting, said casting being provided with a pcripheral cut-out area concentric with one of said counter-bores, said cut-cut area defining a portion of a gas collecting space at the top and an oil collecting space at the bottom of said casting, there being a restricted passageway through said casting between said oil and gas collect! ing spaces and said last named counter-bore, there being a pump discharge opening in said casting in communication with said oil and gas collecting space, whereby oil is forced through said restricted passageway into said first counter bore, and there being a discharge opening in said enveloping gas tight housing above and in communication with said gas collecting space.

2. In a device of the character described, a casting having a central passageway, counterbores at each end of said passageway, end closure members for said counter-bores, a shaft extending through one of said end closure members and through said passageway and into the opposite counter-bore, a rotary compressor assembled in said last named counter-bore and arranged to be driven by said shaft and a gas tight housing enveloping all but one side of said casting, there being a substantially large reservoir adapted to hold oil and. refrigerant formed between one of said end closure members and said gas tight housing, a pump discharge opening communicating with said reservoir, there being a restricted passageway through said last named end closure member and communicating between said reservoir and the interior of said counter-bore containing said compressor assembly, at a point above the oil level in said reservoir, whereby metered amounts of oil are withdrawn from said reservoir and discharged into the counter-bore containing the rotary compressor upon each revolution of the rotor of said compressor.

3. In a device of the character described, the combination of a body having a central longitudinal opening, a large and a small counterbore in said opening, a drive shaft in said opening and having one end extending outside said body, an eccentric cam member on said shaft, double bearings in said body for said shaft, a hardened steel liner ring in said large counterbore, said ring having intake and exhaust passageways therein, flanged rings cooperating with said liner ring to form a closed compartment in said body, a rotor slidably mounted at one end of said shaft and rotatable thereby in said closed compartment, radial slots in said rotor, vanes slidable in said slots, rollers carried by said vanes and arranged to be guided in part by said flanged rings and said eccentric cam, an end closure member for said body having a hub arranged to help guide said rollers, and a gas tight housing enveloping said body but spaced therefrom throughout a substantial area of said body, said housing having a discharge opening above said small counter-bore and a deflector on its inside wall above and in spaced relation to the exhaust passageway in said liner ring, and an outlet in said body from said large counterbore in communication with the exhaust passageway in said ring.

4. The combination defined in claim 3, in which said housing is provided with an abutment ring arranged to be contacted by one end of said body, whereby upon the increase of pressure within said housing said body is brought into closer contact with said ring to efiect a seal therebetween.

5. The combination defined in claim 3, in which said body is provided with a peripheral cut away portion, which together with the housing defines an oil and gas collector area.

6. The combination defined in claim 3, in which said body is provided with a peripheral cut away portion, which together with the housing defines an oil and gas collector area.

7. The combination defined in claim 3, in which said housing has an intake opening in direct communication with the intake passageway in said liner ring.

LEONARD F. CLERC.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,336,845 Kutchka Apr. 13, 1920 1,526,449 Wishart Feb. 17, 1925 1,776,921 Moessinger "Sept. 30, 1930 1,897,547 Buenger Feb. 14, 1933 1,967,035 Lipman July 17, 1934 1,989,864 Jaworowski Feb. 5, 1935 2,289,441 LeValley et a1 July 14, 1942 2,335,284 Kendrick Nov. 30, 1943 2,465,887 Larsh Mar. 29, 1949 

